It is known in the art to fabricate modular units of concrete for assembly into arrays as in Patent Application Ser. No. 828312 wherein load distributing plates of hardened substance are comolded with the concrete to dissipate point stresses on the abutting surfaces.
The present invention likewise utilizes load distributing surfaces which are comolded with the concrete of the modular unit.
In the present invention, however, the points of contact of the load distributing surfaces of adjacent units are three in number. These three points of contact form a plane of contact which exhibits exceptional stability with a reduced cost over extensive metal contact surfaces.
Also in the present invention by virtue of the geometric placement of the holes through which the stressing rods are passed, there is created an increased ease of fastening of the modular units at those points where one planar array of the units meets another array as in the formation of the corner of a building.